<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta
    name="viewport"
    content="width=device-width, initial-scale=1.0"
  >
  <title>chatRoom Server</title>
</head>

<body>

  this is chatRoom Server.
  <button id="sendBtn">test</button>
  <!-- <script src="../../../node_modules/socket.io/client-dist/socket.io.js"></script> -->
  <script>
    // var socket = io.connect(),
    //   button = document.getElementById('sendBtn');
    // button.onclick = function () {
    //   // console.log(this)
    //   socket.emit('foo', 'hello');
    // }
  </script>
</body>

</html>